Attachment 127590 Details for Bug 97994 – [PATCH] drm/i915: Assuming non-DP++ port if dvo_port is HDMI and there's no AUX ch specified in the VBT

[patch] [PATCH] drm/i915: Assuming non-DP++ port if dvo_port is HDMI and there's no AUX ch specified in the VBT

0001-drm-i915-Assuming-non-DP-port-if-dvo_port-is-HDMI-an.patch (text/plain), 4.78 KB, created by Ville Syrjala on 2016-10-28 17:22:10 UTC

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Creator: Ville Syrjala

Created: 2016-10-28 17:22:10 UTC

Size: 4.78 KB

patch

obsolete

>From 213f658d2c23fe2b1b257f04f8176085cd5680ee Mon Sep 17 00:00:00 2001
>From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
>Date: Thu, 27 Oct 2016 21:59:05 +0300
>Subject: [PATCH] drm/i915: Assuming non-DP++ port if dvo_port is HDMI and
> there's no AUX ch specified in the VBT
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>My heuristic for detecting type 1 DVI DP++ adaptors based on the VBT
>port information apparently didn't susrvive the reality of buggy VBTs.
>In this particular case we have a machine with a natice HDMI port, but
>the VBT telsl us it's a DP++ port based on its capabilities.
>
>The dvo_port information in VBT does claim that we're dealing with a
>HDMI port though, but we have other machines which do the same even
>when they actually have DP++ ports. So that piece of information alone
>isn't sufficient to tell the two apart.
>
>After staring at a bunch of VBTs from various machines, I have to
>conclude that the only other semi-reliable clue we can use is the
>presence of the AUX channel in the VBT. On this particular machine
>AUX channel is specified as zero, whereas on some of the other machines
>which listed the DP++ port as HDMI have a non-zero AUX channel.
>
>I've also seen VBTs which have dvo_port a DP but have a zero AUX
>channel. I believe those we need to treat as DP ports, so we'll limit
>the AUX channel check to just the cases where dvo_port is HDMI.
>
>If we encounter any more serious failures with this heuristic I think
>we'll have to have to throw it out entirely. But that could mean that
>there is a risk of type 1 DVI dongle users getting greeted by a
>black screen, so I'd rather not go there unless absolutely necessary.
>
>Cc: Daniel Otero <daniel.otero@outlook.com>
>Cc: stable@vger.kernel.org
>Fixes: d61992565bd3 ("drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT")
>Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97994
>Signed-off-by: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>---
> drivers/gpu/drm/i915/intel_bios.c     | 32 ++++++++++++++++++++++++--------
> drivers/gpu/drm/i915/intel_vbt_defs.h |  3 ++-
> 2 files changed, 26 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
>index 5ab646ef8c9f..33ed05186810 100644
>--- a/drivers/gpu/drm/i915/intel_bios.c
>+++ b/drivers/gpu/drm/i915/intel_bios.c
>@@ -1147,7 +1147,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
> 	if (!child)
> 		return;
> 
>-	aux_channel = child->raw[25];
>+	aux_channel = child->common.aux_channel;
> 	ddc_pin = child->common.ddc_pin;
> 
> 	is_dvi = child->common.device_type & DEVICE_TYPE_TMDS_DVI_SIGNALING;
>@@ -1677,7 +1677,8 @@ bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port)
> 	return false;
> }
> 
>-bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port)
>+static bool child_dev_is_dp_dual_mode(const union child_device_config *p_child,
>+				      enum port port)
> {
> 	static const struct {
> 		u16 dp, hdmi;
>@@ -1691,22 +1692,37 @@ bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum por
> 		[PORT_D] = { DVO_PORT_DPD, DVO_PORT_HDMID, },
> 		[PORT_E] = { DVO_PORT_DPE, DVO_PORT_HDMIE, },
> 	};
>-	int i;
> 
> 	if (port == PORT_A || port >= ARRAY_SIZE(port_mapping))
> 		return false;
> 
>-	if (!dev_priv->vbt.child_dev_num)
>+	if ((p_child->common.device_type & DEVICE_TYPE_DP_DUAL_MODE_BITS) !=
>+	    (DEVICE_TYPE_DP_DUAL_MODE & DEVICE_TYPE_DP_DUAL_MODE_BITS))
>+		return false;
>+
>+	if (p_child->common.dvo_port == port_mapping[port].dp)
>+		return true;
>+
>+	/* Only accept a HDMI dvo_port as DP++ if it has an AUX channel */
>+	if (p_child->common.dvo_port == port_mapping[port].hdmi &&
>+	    p_child->common.aux_channel != 0)
>+		return true;
>+
>+	return false;
>+}
>+
>+bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port)
>+{
>+	int i;
>+
>+	if (port == PORT_A)
> 		return false;
> 
> 	for (i = 0; i < dev_priv->vbt.child_dev_num; i++) {
> 		const union child_device_config *p_child =
> 			&dev_priv->vbt.child_dev[i];
> 
>-		if ((p_child->common.dvo_port == port_mapping[port].dp ||
>-		     p_child->common.dvo_port == port_mapping[port].hdmi) &&
>-		    (p_child->common.device_type & DEVICE_TYPE_DP_DUAL_MODE_BITS) ==
>-		    (DEVICE_TYPE_DP_DUAL_MODE & DEVICE_TYPE_DP_DUAL_MODE_BITS))
>+		if (child_dev_is_dp_dual_mode(p_child, port))
> 			return true;
> 	}
> 
>diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h
>index 68db9621f1f0..8886cab19f98 100644
>--- a/drivers/gpu/drm/i915/intel_vbt_defs.h
>+++ b/drivers/gpu/drm/i915/intel_vbt_defs.h
>@@ -280,7 +280,8 @@ struct common_child_dev_config {
> 	u8 dp_support:1;
> 	u8 tmds_support:1;
> 	u8 support_reserved:5;
>-	u8 not_common3[12];
>+	u8 aux_channel;
>+	u8 not_common3[11];
> 	u8 iboost_level;
> } __packed;
> 
>-- 
>2.7.4
>

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Attachments on bug 97994: 126917 | 126918 | 126928 | 126959 | 127590

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